PCI: Remove unused SR-IOV VF Migration support

This reverts commit 74bb1bcc7dbb ("PCI: handle SR-IOV Virtual Function
Migration"), removing this exported interface:

  pci_sriov_migration()

Since pci_sriov_migration() is unused, it is impossible to schedule
sriov_migration_task() or use any of the other migration infrastructure.

This is based on Stephen Hemminger's patch (see link below), but goes a bit
further.

Link: http://lkml.kernel.org/r/20131227132710.7190647c@nehalam.linuxnetplumber.net
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Stephen Hemminger <stephen@networkplumber.org>

2 files changed, 0 insertions, 123 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 9dce7c5e2a77..de7a74782f92 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -170,97 +170,6 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset)
         pci_dev_put(dev);
 }
 
-static int sriov_migration(struct pci_dev *dev)
-{
-        u16 status;
-        struct pci_sriov *iov = dev->sriov;
-
-        if (!iov->num_VFs)
-                return 0;
-
-        if (!(iov->cap & PCI_SRIOV_CAP_VFM))
-                return 0;
-
-        pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
-        if (!(status & PCI_SRIOV_STATUS_VFM))
-                return 0;
-
-        schedule_work(&iov->mtask);
-
-        return 1;
-}
-
-static void sriov_migration_task(struct work_struct *work)
-{
-        int i;
-        u8 state;
-        u16 status;
-        struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
-
-        for (i = iov->initial_VFs; i < iov->num_VFs; i++) {
-                state = readb(iov->mstate + i);
-                if (state == PCI_SRIOV_VFM_MI) {
-                        writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
-                        state = readb(iov->mstate + i);
-                        if (state == PCI_SRIOV_VFM_AV)
-                                virtfn_add(iov->self, i, 1);
-                } else if (state == PCI_SRIOV_VFM_MO) {
-                        virtfn_remove(iov->self, i, 1);
-                        writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
-                        state = readb(iov->mstate + i);
-                        if (state == PCI_SRIOV_VFM_AV)
-                                virtfn_add(iov->self, i, 0);
-                }
-        }
-
-        pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
-        status &= ~PCI_SRIOV_STATUS_VFM;
-        pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
-}
-
-static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
-{
-        int bir;
-        u32 table;
-        resource_size_t pa;
-        struct pci_sriov *iov = dev->sriov;
-
-        if (nr_virtfn <= iov->initial_VFs)
-                return 0;
-
-        pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
-        bir = PCI_SRIOV_VFM_BIR(table);
-        if (bir > PCI_STD_RESOURCE_END)
-                return -EIO;
-
-        table = PCI_SRIOV_VFM_OFFSET(table);
-        if (table + nr_virtfn > pci_resource_len(dev, bir))
-                return -EIO;
-
-        pa = pci_resource_start(dev, bir) + table;
-        iov->mstate = ioremap(pa, nr_virtfn);
-        if (!iov->mstate)
-                return -ENOMEM;
-
-        INIT_WORK(&iov->mtask, sriov_migration_task);
-
-        iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
-        pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
-
-        return 0;
-}
-
-static void sriov_disable_migration(struct pci_dev *dev)
-{
-        struct pci_sriov *iov = dev->sriov;
-
-        iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
-        pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
-
-        cancel_work_sync(&iov->mtask);
-        iounmap(iov->mstate);
-}
-
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
         int rc;
@@ -351,12 +260,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
                         goto failed;
         }
 
-        if (iov->cap & PCI_SRIOV_CAP_VFM) {
-                rc = sriov_enable_migration(dev, nr_virtfn);
-                if (rc)
-                        goto failed;
-        }
-
         kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
         iov->num_VFs = nr_virtfn;
 
@@ -387,9 +290,6 @@ static void sriov_disable(struct pci_dev *dev)
         if (!iov->num_VFs)
                 return;
 
-        if (iov->cap & PCI_SRIOV_CAP_VFM)
-                sriov_disable_migration(dev);
-
         for (i = 0; i < iov->num_VFs; i++)
                 virtfn_remove(dev, i, 0);
 
@@ -688,25 +588,6 @@ void pci_disable_sriov(struct pci_dev *dev)
 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 
 /**
- * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
- * @dev: the PCI device
- *
- * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
- *
- * Physical Function driver is responsible to register IRQ handler using
- * VF Migration Interrupt Message Number, and call this function when the
- * interrupt is generated by the hardware.
- */
-irqreturn_t pci_sriov_migration(struct pci_dev *dev)
-{
-        if (!dev->is_physfn)
-                return IRQ_NONE;
-
-        return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
-}
-EXPORT_SYMBOL_GPL(pci_sriov_migration);
-
-/**
  * pci_num_vf - return number of VFs associated with a PF device_release_driver
  * @dev: the PCI device
  *
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4df38df224f4..6bd082299e31 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -1,8 +1,6 @@
 #ifndef DRIVERS_PCI_H
 #define DRIVERS_PCI_H
 
-#include <linux/workqueue.h>
-
 #define PCI_CFG_SPACE_SIZE      256
 #define PCI_CFG_SPACE_EXP_SIZE  4096
 
@@ -240,8 +238,6 @@ struct pci_sriov {
         struct pci_dev *dev;    /* lowest numbered PF */
         struct pci_dev *self;   /* this PF */
         struct mutex lock;      /* lock for VF bus */
-        struct work_struct mtask; /* VF Migration task */
-        u8 __iomem *mstate;     /* VF Migration State Array */
 };
 
 #ifdef CONFIG_PCI_ATS